Gel electrophoresis is a technique used for the separation of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), or protein molecules using an electric field applied to a gel matrix. DNA Gel electrophoresis is performed for analytical and preparative purposes, often after amplification of DNA via polymerase chain reaction (PCR) or restriction digest of DNA and as a preparative technique prior to use of other methods such as mass spectrometry, RFLP, PCR, cloning, DNA sequencing, or Southern blotting for further characterization.
Generally, after the separation by electrophoresis is complete, the molecules in the gel can be stained to make them visible. Common reagents such as ethidium bromide, GelRedm Sybr Green, Sybr Safe, Gel Green, silver, or Coomassie “blue dye” may be used for this process. Other methods may also be used to visualize the separation of the mixture's components on the gel. If the analyte molecules fluoresce under ultraviolet light, a photograph can be taken of the gel under ultraviolet lighting conditions. If the molecules to be separated contain radioactivity added for visibility, an autoradiogram can be recorded of the gel.
Illuminators useful for visualization of fluorophores are known in the art. For example, U.S. Pat. No. 5,347,342 discloses a transilluminator with UV light enclosed in a housing having a UV-transmissible window and a means for reflecting an image of the UV light source through the window in a manner that causes the UV light source to appear to be a multiple light source, while U.S. Pat. No. 5,327,195 describes a transilluminator with a UV light source enclosed in a housing having a UV-transmissible window with a removable protector plate overlying the window. U.S. Pat. No. 5,363,854 describes an apparatus for detecting anomalies of the skin by utilizing light in an ultraviolet wavelength range during a first time interval and with light in a visible wavelength range during a second time interval. U.S. Pat. Nos. 6,198,107, 6,512,236 and 6,914,250 describes a transilluminator system for viewing fluorescently stained DNA, protein or other biological material with a light source that requires at least two optical filters wherein a first optical filter is disposed between the light source and the fluorescent material being viewed and a second optical filter disposed between the fluorescing material and the viewer. The complete disclosure content of all patents and publications mentioned above are incorporated into this application by way of reference.
Therefore a need exists for apparatus and methods that utilize UV or visible light for the visualization of fluorophores wherein the apparatuses and methods require no optical filter between the light source and the fluorescent material being viewed; are compact or easily portable; and are adaptable to a variety of environments such as gel electrophoreses, cell-culture gels and the like.